Electrical submarine torpedo



Nov. 22, 1960 s. BENNON ETAL 2,960,956

ELECTRICAL SUBMARINE TORPEDO Filed Sept. 23, 1950 2 Sheets- Sheet 1 uss 150 I52 I54 2 N I -|34 205 ELECTRONIC: Two DIFFERENTIAL swrrcu WITCH STAGE DETECTOR I AND A.c.

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- c. AND UT I AWL v VERTICAL V gq cmcurr 1 amuse w DEV|QE FIER CIRCUIT l /|7l I 39 /38 INVENTORS 37 SAUL BENNON 1 v FREDERICK H. HOFING ATTORNEY Nov. 22, 1960 I s. BENNON ETAL 2,960,956

ELECTRICAL SUBMARINEZ TORPEDO 2 Sheets-Sheet; 2

| ANTI-CIRCULAR IRON AND SAFETY :cu'r-ou'r DEVICE Filed Sept. 23, 1950 I33 Ffil STARBOARD PENDULUM swn'cu UNIT 37 INVENTORS.

' SAUL BENNON FREDERICK H HOFING ORNEY ELECTRICAL 'SUBMARINE TORPEDO Saul Bennon, Sharon, and Frederick H. Hofing, Sharpsvill'e, Pa., assignors, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Filed June 23, 1950, Ser- No. 169,876

'24 Claims. (Cl. 114-23) This invention relates to the electrical control system of .an acoustic torpedo for submarine use, and it is more particularly described as an acoustic homing tor- .pedo .provided with electronic controls to reduce the effect of normal firing errors by guiding the torpedo to the source of water-borne sound energy. Its advantages over a standard electric torpedo are its ability to turn -a normal miss into a hit, and its ability to hit a shallow draft target such as a surface vessel.

An important object of the invention is to provide an all electric control for an acoustic submarine torpedo.

A further object of the invention is to provide an electrical control system for a torpedo which is effective during the time between firing and the take-over of the acoustic operation and also during :the acoustic operation.

A still further object of the invention is to provide an electrically operated torpedo having acoustic gear which is enabled to take over the torpedo .control after a :predetermined time.

Still a further object of the invention is to provide protective andsafety elements andacircuits and to prevent operation of the acoustic circuits until the torpedo is "out of the effective sound field of the submarine which fired it.

Gther objects of the invention will appear in the specilication and will be apparent from the accompanying drawings, in which,

The figure is a diagrammatic representation of the circuits, connections, and devices in a control system for an electrical acoustic submarine torpedo in accordance with this invention.

The invention is described as applied to a submarine torpedo of standard twenty-one inch diameter, made and assembled in sections, and completely powered and operated by electrical energy. Many of the electrical and mechanical parts are not herein described in structural details 'as these are subject 'to alteration during develop- 'ment, but they are sutiiciently shown and described to include the circuits, connections and operations which constitute the system.

Referring now more particularly to the drawings, a starting lever is mounted in a torpedo to project outwardly from the wall so it may be moved from the outside thereof. When thus operated the lever closes a starting lever switch 11 which completes circuits to a gyro motor 12 and to a starting relay 13 from a storage battery 14. These circuits are from the plus end of the battery through conductor 15 and switch 11 to one side -'of the gyro motor 12 and to the starting relay 13 through an auxiliary starting relay switch 19; thence through the gyro motor, a gyro interrupter switch 16, a conductor 17, a motor "disconnect switch 18 and a battery main 20 to the negative side of the battery; and from the relay 13 through a conductor 21 to the negative battery main 20. energized as 'soon as the switch 11 is closed as later set forth.

The auxiliary starting relay 218 is also 2,960,956 Patented Nov. 22, 1960 After a running time of approximately one-third of a second the gyro motor brings the gyro wheel up to 12,000 or 13,000 r.p.m., disconnects the motor from the gyro wheel, which continues to spin freely, and opens the gyro interrupter switch 16 through a connection 22 therewith.

Energizing the relay 13 closes its switch 23 which completes circuit from battery conductor 15 through the switch and conductor 24 to a motor start relay 25 and conductor 26 to the negative battery main .20. This relay closes a switch 27 connecting a propulsion motor 30 directly to the positive battery conductor 15 at one side and through the motor disconnect switch 18 to the negative battery main 20 at the other side.

The motor start switch relay 25 is a solenoid type to delay starting of the propulsion motor 30 until the gyro motor is started and disconnected, and until the torpedo is out of its propulsion tube. A time delay for closure of the switch 27 of approximately one second after the solenoid is energized is provided to avoid 'excessive current loads on the storage battery, which would be the case if the gyro and propulsion .motors were started simultaneously.

When the starting relay 13 closes its switch 23, a circuit is closed through a filament relay 31 from the battery 14 by way of the conductor 24 and a conductor 32, and from the relay winding to the battery main 29 by the conductor 33. This closes filament switches .34, 35, and 36 which close circuits from battery main 20 to conductors 37, 38, and 39 respectively extending to electronic tube filament heaters as hereinafter set forth.

The propulsion motor 30 is connected by a driving shaft40 with a propeller 41 mounted in the torpedo tail cone and has a distance gear comprising a worm pinion 42 on the shaft and a worm gear 43 adapted to mesh therewith and having a low portion 44 devoid of teeth. Attached to the gear 43 is .a cam 45 having a low contact portion 46 which, after CCW rotation of cam45, faces the follower stern of contact switch 47 so that the latter is actuated to connect the battery main 20 with a conductor 48 extending to a distance relay 50 and through the winding thereof to a ground connection. This in .turn operates a distance relay switch 51 closing an energizing circuit through an enabler relay 52 having a winding connected by a conductor 53 to the storage battery main 20 and 'by a conductor 54 through the distance relay switch 51 to the distance relay ground connection. By setting the worm gear 43 so that the low portion 44 will reach the pinion '42 after a number of rotations of the driving shaft 40 the approximate distance the torpedo travels before closing the switch 47 may be predetermined.

The torpedo is now under way controlled by its gyro and a depth control or pendulum switch unit as hereinafter described. The controls are ordinarily set .for an eighty-foot running depth. A depth disarming switch 58, also, is located in an exploder circuit, receives external fluid pressure, and is maintained thereby in open position until the torpedo'rises above sixty feet below the surface.

In the exploder circuit is an extension of the battery conductor main 20 which leads to a fixed block having a normally open inertia switch 61. The switch is connected to a conductor 62 which extends to the depth disarming switch 58 having a fluid pressure operator represented by a bellows 63. At the lower side or bottom of the torpedo is an exploder safety chamber 64 communicating with the outside sea pressure, and with an inner detonator 65 having terminals .66 normally .connected by a safetybar 67. The detonator is adapted to extend into a booster cavity 68 and, by impeller wheel mechanism (not shown), to be raised out of the safety chamber to separate the terminals from the short circuiting safety bar 67 into engagement with conductor terminals 70 and 71. One terminal 70 is at the end of a conductor 72 extending to the switch 58, and the other terminal 71 is at the end of a conductor 73 extending to the grounded distance switch 51 side of the distance relay 50.

After the torpedo has traveled a predetermined distance, approximately 500 yards, the exploder becomes armed. That is, the detonator 65 is then raised into the booster cavity 68, separating the detonator terminals 66 from the safety bar 67 and connecting it into the firing circuit by engagement of the terminals 66 with the terminals 70 and 71. The fixed block 60 of the inertia switch is connected to an extension of the battery main 20, but the firing circuit still has two points of discontinuity, at the depth disarming switch 58 and at the inertia switch.

When the torpedo has traveled a predetermined distance, perhaps 1000 yards, the distance gear 43 has rotated counterclockwise and its cam 45 closes the distance switch 47, and energizes the winding of distance relay 50. This closes a circuit from the battery main 20, through switch 47, conductor 48, and distance relay winding to ground. Closing of the switch 51 completes an energizing circuit through the winding of the enabler relay 52 which is traced from battery main 20, conductor 53, relay winding, conductor 54, and distance relay switch 51 to the grounded side of the distance relay.

Operation of the enabler relay makes the torpedo capable of homing on an acoustic target and sets up the operation of the auxiliary control units. During the first 1000 yards the torpedo is unable to respond to an acoustic signal and is guided solely by the gyro and depth control mechanism. The torpedo continues under gyro and depth pendulum control after becoming acoustically enabled until it enters the sound field of the target.

Gyro steering.-In steering in azimuth, the torpedo oscillates or swerves slightly from one side to the other .of the direct path due to the operation of a gyro switch 80, a gyro relay 81, and a gyro-repeater relay K1. The gyro switch is represented as having a relatively fixed conductor section 82 which is adjustable for angle shots of the torpedo, and a connected non-conducting section 83, the two sections forming a ring to which a contact 84 is relatively movable by the gyro action. The junction line of the two sections is the switching point and the contact 84 connected to the outer gyro gimbal hunts on this line when the torpedo is on its gyro course. When the contact 84 bears on the insulated section, as when off-course to port, starboard rudder is obtained, and when on the conductor section 82, as when off-course to starboard, port rudder is obtained.

If the torpedo goes off course to port or to starboard, a circuit is closed from the battery main 20, through conductor 85 to the contact ring section 82, thence through a conductor 86, to the winding of the gyro relay 81, and from the winding through conductor 87, a resistance 88 and a conductor 89 to ground. If the contact 84 makes engagement with the conductor section 82, as when the torpedo goes off-course to starboard, the winding of the gyro relay 81 is short circuited through conductor 86, contact ring section 82, contact 84, and conductor 87.

When the torpedo goes olf course to port, gyro relay 81 is energized to close its switch 90 thereby energizing the K1 relay and closing its switch 91 to complete a circuit through a rudder relay 92. This circuit is from the battery main 20 through conductor 93, winding of rudder relay 92, conductor 94, conductor 95, switch 91 of K1 relay, conductor 96, switch 97 of enabler relay 52, and conductor 98 to ground. When the torpedo goes olf course to starboard, the K1 relay is not energized and direct current amplifiers.

its switch 91 opens, thereby opening its circuit and do energizing the rudder relay 92.

A switch 100 operated by the rudder relay has one terminal 101 connected by a conductor 102 with a starboard solenoid coil 103, and an opposite terminal 104 connected by a conductor 105 with a port solenoid coil 106. The other end of each coil is connected by a common conductor 107 with battery main 20, and the rudder relay switch 100 is connected by a conductor 108 with the other battery terminal represented by a ground. When the rudder relay is energized the switch 100 closes a circuit through the starboard rudder coil 103, and when the relay is deenergized, the switch 100 closes a circuit through the port rudder coil 106. Energizing one coil or the other causes a corresponding movement of a rudder 110 operated thereby. The rudder mechanism is represented as comprising connected solenoid cores actuated by the starboard and port solenoid coils to move the rudder 110 accordingly.

Depth control.The depth control mechanism comprises a hydrostat 112 and a pendulum 113 mechanically linked together, the hydrostat represented as bearing upon an angular arm of the pendulum. Connected to the pendulum is a contact 114 having a conductor 120 extending therefrom, and a corresponding fixed contact 118 is connected by a conductor 115 to one end of the winding of an elevator relay 116. The other end of the winding is connected by a conductor 117 with the battery main 20, and when the depth pendulum is closed the contact 114 makes connection with the fixed contact 118. The pendulum contact 114 is connected by the conductor 120 to a terminal 121 of vertical steering relay K4, and also to a switch terminal 122 for a switch 123 of the enabler relay 52 by which the circuit is connected to a ground.

-The elevator relay 116 has a switch 124 for engaging either the terminal of a conductor 125 when the relay is energized or that of a conductor 126 when the pendulum contacts are separated and the circuit to the relay 116 is opened. The conductor 125 is connected to one terminal of a down coil 127 and the conductor 126 is connected to one terminal of an up coil 128, the other terminals of the coils being connected by a common conductor 129 with the battery main 20. When the depth pendulum contacts are closed the elevator relay and the down coil are energized to turn an elevator rudder 130 to guide the torpedo downwardly, and when the pendulum is rocked to separate the contacts 114 and 118 the up coil 128 is energized to turn the elevator rudder 130 in a direction to guide the torpedo upwardly. The elevator rudder mechanism is represented as similar to the steering rudder mechanism, and since the control is an on-ofi mechanism, the torpedo usually travels in a vertical oscillatory path.

The hydrostatic device 112 modifies the pendulum movement at times, maintaining the contacts 114, 118 together, for example, before the torpedo has attained its normal set depth (of 80 feet) and swinging the pendulum to open position even if the torpedo is on an even keel if it is below the set depth.

Acoustic c0ntr0l.The acoustic control equipment comprises port and starboard hydrophones in the torpedo nose for horizontal steering and upper and lower hydrophones for vertical steering. The two hydrophones of each pair are connected alternately to the input of a single amplifier channel, and each channel comprises an alternating current amplifier, a differential detector, and a direct current amplifier whose output controls the horizontal or vertical steering coils.

In the differential detectors are bridge circuits that determine the biasing voltages applied to the connected The bridge circuits are considered to be balanced when control relays K3 for horizontal steering and K4 for vertical steering are at the operating point so that an ncoming signal will produce steering action. The horizontal bridge 'ClICll-lt (K3) is connected to the vertical steering channel for locking out the gyro control when the torpedo is in full acoustic response to the target.

.on the port side (contacts closed.).,the.gyro relay is 'shortcircuited and therefore release'dythe K1 relay is in the released position, the rudder relay'92;is in released position, andpower is applied to the port'rudder coil '106, actuating the rudder 110 togport. When the. gyro switch is tostarboard (open), the gyrosrelay is :operated, which actuates thexKl relay, 'energizing'the rudder relay'to supply power'tothe starboard'winding coil, actuating the rudder (or rudders) to starboard.

Horizontal contrl(b) After enabling-No sound field.-At the end of the pre-set enabling distance, the distance switch 47 closes to energize the distance relay 50 and the enabler relay 52. The rudder relay 92 then receives steering impulses from the horizontal control relay K3. -While the upper contact switch 91 on the K1 relay no longer controls the rudder relay, a lower contact switch 131 controls the K3 relay in the absence of an effective sound field, so that the gyro, in effect, through the K1 relay still controls the steering through a gyro bucking differential circuit.

Gyro bucking difierential circuit.--In this differential circuit are terminals B1 and B2 separated by a balancing potentiometer P3 and connected by conductors 133 and 134 respectively with a horizontal channel bridge circuit as hereinafter described. Opposite terminals 135 and 136 are each connected to terminals B1 and B2 through resistances R1 and R2, respectively, and between the on posite terminals is a resistance R3. Connected to the terminals 135 and 136 are conductors 137 and 138 having contact terminals above and below the switch 131 of the K1 relay respectively to close either contact depending upon the energization or release of the relay in step with the gyro relay. From the opposite terminals 135 and 136, resistances R4 and R connect them with a terminal 140 which has a terminal conductor 141 for engaging a switch 142 of a relay K2. The switch 131 of the relay .Kl has a conductor 143 connecting it with a release terminal 144 of the relay K2 switch 142. Extending from the potentiometer P3, is a conductor 145 connected through a resistance R6 to this switch 142, which is also connected by a conductor 146 to ground through a resistance R7.

As the relay K1 operates and releases in step with the gyro relay and switch, first one side and then the other of P3 is connected to the ground through a resistance (R4 or R5) which parallels the resistance R6 also to the ground. The effect of this is to unbalance the bridge of the horizontal acoustic channel, first on one side and then on the other through conductors 133 and 134 to cause the relay K3 to step in unison with K1. That is with K1 released, the bridge is unbalanced in the direction to cause K3 to be released; and when K1 is operated the bridge unbalance is reversed to cause K3 to be operated.

Horizontal control after enabling(c) With effective sound field.When the torpedo enters a circular sound field on a chord of the circle, the hydrophones pick up the sound energy alternately from port and starboard at the electronic switching frequency of 225 cycles per second. The port and starboard hydrophones are connected to an electronic switch and circuit device 150, and thence to a two-stage A.C. amplifier 152 and to a differential electronic switch, detectorand a horizontal bridge circuit device 154, and thence through a DC. amplifier 156, and

through conductors 157 and 158 therefrom to the winding of the K3 relay. The port and starboard energy impulses, or signals, received from the hydrophones, are

U independently amplified 'and fed through the differential detector and bridge circuit for controlling'the relay'K3. When the'bridge circuit .controlledby the K1 relay is at initial steady balance, which-is the case when the K2 ceived-through conductors 157 and 158. This closes .a

switch 160 andsince the enabler relay 52 is also energized,

:the 'upper switch 97 is closed thereby and a circuit is closedifrom the'battery main 20, through conductor .93,

rudder relay 92 winding, conductor 94, switch 160, conductor-164, switch97, an'd'conductor98 to ground.

Sound operating conditions.In its initial entry into a sound field, thetorpedo is 'being steered in its gyro course through the action of the K3 relay operating in step'with the gyro'relay. The sound field must be able to produce sufficient differential input totake control by the K3 relay away from the K1 and gyro relays. The hydrophone circuit values are adjusted sothat approximately 4.5 decibels differential input is requiredifor the hydrophones to take control from the gyro relay.

The effective target field noise level must be at least 3 decibels above the self noise of the'torpedo in order for the hydrophones to take control; this self. noise is reduced at greater depths, and it is for'this reason that the normal running depth of thetorpedo'is set .at '80 feet.

gyro course unless the gyro lockout has been operated.

The horizontal homing action occurs in general before vertical homing, so that the torpedo does not rise tothe target until after it is in horizontal pursuit.

Vertical control-The vertical control channel comprises up and down hydrophones connected to an electronic switch and input circuit device 166, thence through a two stage A.C. amplifier 167 to a differential electronic switch detector and vertical bridge device 168, and through a DC. amplifier 170 and a conductor 171 'to one end of the winding of the K4 vertical steering relay. The other end of the winding is connected by aconductor 172 with a conductor 158 leading from the horizontal D.C. amplifier 156 to one end of the winding of the horizontal steering relay K3.

Before the enabler relay 52 is operated, the elevator relay 116 receives current through the depth pendulum unit and by way of conductor 120, and relay switch 123 of the enabler relay to ground. When the enalbler relay 52 is energized this switch connection is opened, but the switch then makes a connection with a conductor 173 connected to a switch 174 of the vertical steering relay which then is moved to make connection with the terminal 121 of the conductor 120 connecting it to the same ground through switches 174 and 123 and the conductor 173.

This K4 relay is controlled by the vertical channel differential detector and bridge circuit. Sound energy signals are fed alternately from the upper and lower hydrophones to this circuit. When the bridge is in initial balance, an up differential signal at the detector circuit will unbalance'the'bridge to release the K4 relay, and a down dilferential signal will energize the K4 relay attracting its switch 174.

The bridge circuit is adjusted by inserting an 8- decibel loss network 175 between the up hydrophone and the switch device 166 in the vertical hydrophone channel, to produce a slightly unbalanced condition in the direction to operate the K4 relay. In the absence of sound input during deck testing, the K4 relay will remain closed and allow the depth switch (pendulum) to control the elevator relay 116. In an underwater run, in order for the upper and lower signal inputs to be equal at the detector circuit device 168, the sound energy input to the up hydrophone must exceed the input to the down hydrophone by the amount 8 decibels. The result desired is to hold the torpedo at its normal running depth until it is close to the target to eliminate premature broaching.

Vertical operation-The torpedo approaches a target at its set depth, but when it reaches a position where the target is about 15 above the axis of the torpedo, the input to the up hydrophone will be sufliciently greater than the input to the down hydrophone to release the K4 relay. This release interrupts the circuit through switch 174 between the conductors 120 and 173, and if the enabler relay 52 is energized, its switch 123 opens connection from the conductor 120 terminal 122 to ground, and regardless of the position of the depth pendulum switch. This release energizes the winding 128 to actuate the elevator rudder to up position.

When the torpedo begins to rise, the depth pendulum switch closes and as the torpedo continues to rise toward the target, the up differential at the hydrophones may be enough reduced to close the relay K4. If this occurs the closed depth switch causes the operation of the elevator relay to energize the down winding 127. As the torpedo turns downwardly, the up hydrophone differential is increased, again releasing the K4 relay and causing an up elevator rudder position.

Thus the torpedo is steered vertically to aim about 15 below the sound source. In a stern chase, this causes the torpedo to hit forward of the target ships screws. If a torpedo begins a vertical attack and passes out of the effective field, it will return to its set depth.

With the K4 relay operated, the depth pendulum unit is in control of the vertical steering, and the torpedo can only descend until the depth unit switch opens. A down differential usually exists during the first part of the torpedo travel in a target field due to the 8-decibel loss in the up hydrophone circuit.

Gyro lock-ouL-If the torpedo fails to hit a target upon its first attack, it will tend to head away from the sound source. The hydrophones have low sensitivity to signals from targets rearwardly of the torpedo, and without some provision to remove the gyro bucking diiferential control, the torpedo would lose the target and return to its gyro course and its set depth, and in most cases would run out of the efiective target field.

In the lock-out circuit is an auxiliary gate relay AG having a winding connected at one end by a conductor 176 to engage the switch 174 of the K4 steering relay in its release position, and by a conductor 177 at its other end connected to battery main 20. A switch 178 is connected to the grid of a gas filled tube 180 by a conductor 181 and a condenser 182 is connected across the grid and cathode. The tube plate is connected by a conductor 183 with one end of a winding of a DG relay, the other end being connected by a conductor 184 with the battery main 2%. When the switch 178 is closed the terminal of a conductor 185 is engaged, which has a resistance 136 therein and is connected to the conductor 134 and thence to the battery main 20. The back contact of the switch 173 is connected to one end of a resistance 187, the other end of which is connected by a conductor 188 which extends from the tube cathode to a ground. The DG relay controls a switch 190 connected by a conductor 191 to ground, and when operated it engages a conductor 192 extending to one end of the K2 relay winding in the gyro bucking diiferential circuit, the other end of the winding being connected by a conductor 193 with the battery main 20.

During the first attack gyro-control lockout is provided, with a Z-second time interval based upon the vertical steering action. The K4 vertical steering relay is released only when the torpedo is responding to an acoustic target in the vertical channel. When K4 is released the AG relay is energized through the back control of switch 174 and through conductor 173 and switch 123 of the enabler relay 52 to ground. When the AG relay is energized its switch 178 is closed and voltage is applied to the condenser 182 connected across the grid and cathode of the tube 180. It takes approximately two seconds for the condenser to acquire sufficient charge to fire the gas tube. Once initiated, the plate current of the gas tube is sustained as long as the plate potential is applied. The plate current energizes the DG relay and its contact closes a circuit through the K2 relay. When the K2 switch 142 is closed the gyro bucking transfer contacts of the K1 relay are disconnected from the ground by the switch 142, and the horizontal bridge circuits of the device 154 are placed in steady balance through the delta network of the gyro bucking differential circuit through the conductors 133 and 134 which extend to the device 154. When this occurs only a small differential. input (about /z decibel) is required to effect steering. The circuit then becomes sensitive to the self noise of the torpedo which has enough unbalance to cause response to either side, so that the torpedo circles until attracted by a sound field stronger than its self-noise.

Thus the torpedo has greatly increased chances of reattacking a target. After the breach or target miss, it descends toward the set depth, circles under the influence of self-noise until it picks up a target field. If the vertical response (up-difierential) received from the vertical hydrophone channel, causing release of the K4 relay, does not last more than two seconds, the relay is then energized causing the AG relay to be deenergized and the condenser 182 discharges through the resistance 187. The discharge time allows signals shorter than two seconds to accumulate a breakdown charge, if received in close succession, while widely spaced short signals have no eifect. For this reason short duration extraneous noises will not lock out the gyro.

Tube heating conductors 37, 38 and 39 from the filament relay extend to the vertical input device 166, to the horizontal input device 150, and to other parts of both horizontal and vertical channels, respectively.

Acoustic control circuits.Electronic switching of the hydrophones and the detector circuits is effected with a 225 cycle, tuned plate, push-pull oscillator 195 having output conductors 196 extending to the horizontal hydrophone channel, 197 extending to the vertical hydrophone channel, and 1% extending to the A.C. amplifiers. The horizontal and vertical hydrophone control circuits are substantially identical as far as the switching performance is concerned. In the vertical channel 8 decibels more signal is required in the up hydrophone than in the down hydrophone to give equal inputs to the AC. amplifier 167.

(a) Horizontal.Signals picked up by the horizontal hydrophones are received by the electronic switch and input circuit device 150, the output is fed into the amplifier 152, and alternate spurts of signals are impressed upon the detector and bridge circuit device 154. In effect, there are separate input and detector circuits for each hydrophone with one A.C. amplifier which is switched to join one set of circuits and then the other. The bridge device terminates in the DC. amplifier and controls a horizontal steering relay K3.

When the signal received from the starboard hydrophone is stronger than the port signal the net result of E opens the energizing circuit of the auxiliary starting relay thereby opening the circuit to the winding of the starting relay 13.

Opening of the starting relay 13 winding circuit releases its switch 23 which opens the motor start switch 25 relay winding circuit and this opens its switch 27 causing the motor 40 to stop and the torpedo will sink harmlessly out of the way.

Anti circular action.--If the distance relay 50 is in the proper open condition at firing of the torpedo, the relay A is not energized, and when the motor start switch 27 closes, approximately one second after firing, the relay B is energized by a circuit from the battery main 20, through conductor 204 to the relay winding and through a conductor 221 to motor start switch 27 which also connects this conductor to positive battery main 15. This operates the relay B switch 207 which operates to remove the safety cutout feature by opening the condenser circuit from conductor 210 to conductor 215 through relay A, switch 206.

Two relays C and D have windings connected by conductors 222. and 223 respectively with conductors 102 and 105 leading to the starboard and port rudder windings. The relay C has twin switches 224 and 225, and the relay D has twin switches 226 and 227 operated thereby. Corresponding switches 224 and 226 are joined by a conductor 228 which connects them by conductor 203 with one side of the condenser 201. Each of these switches is connected in release position to the opposite relay winding; that is, switch 224 is connected by a conductor 230 with the winding of relay D, and switch 226 is connected by a conductor 231 with the winding of relay C. Each of the other switches 225 and 227 makes actuated and re lease contacts, the actuated contact of switch 225 being connected by a conductor 232 to a conductor 233 which extends at one end to make an actuated connection with the switch 227 and at the other end to a resistance 234 and thence by a conductor 235 to the switch end of the winding of relay E. The release contact of switch 227 is connected by a conductor 236 with the switch 225, and the release contact of switch 225 is connected by a conductor 238 through a resistance 24% with the cathode side of the condenser 201.

If the rudder relay 92 is in a (release) position to actuate the relay D a circuit is closed from the negative main 20 through conductors 204, 298 and 203 to one side of the condenser 201 and to switch 224 of relay C which is in its release position, through conductor 230, winding of relay D, conductors 223, 195, switch 160 in release position to ground. At this time, the condenser is receiving a charge through resistance 211. In normal steering along a straight gyro course this will persist for somewhat less than one second until the rudder relay 22 reverses to release relay D and to energize relay C. This circuit for relay C is traced from conductor 2&3 at the negative side of the condenser 291 through conductor 228, switch 226, conductor 231, winding of relay C, conductors 222, 102, to the ground through rudder relay switch 100.

Before the relay C can operate, the relay D must be released. For every steering winding (103 or 1%) transfer of energization, there will be an instant when both of the relays C and D will be released simultaneously. Durring this instant the condenser 26-1 is discharged through conductor 238 and resistance 240, back contact of switch 225, conductor 236, switch 227, and conductor 262 to the other side of the condenser 291.

As soon as the other relay C is operated, the condenser charging is again started through resistance 211. Under normal operation this cycle will be repeated about once per second until the torpedo has traveled the distance determined by the distance switch setting. The intervals of charge will not be sufficient to fire the tube. The regular operation .of the distance switch 47 and its relay 50 will operate the enabler relay 52 and also the relay A which removes the charging voltage from the circuit,

i2 effectively removing the ACR-SC device, and leaving the torpedo free to maneuver when influenced by sound from a target.

If it is assumed that the torpedo begins to circle after it is fired and before operation of the distance switch, one of the relays C or D will then be energized and continuously operated for an interval of time at least equal to that necessary for the torpedo to turn for in a tight circle. That time is sufiicient for the condenser 201 to be charged through resistance 211 to the breakdown voltage of the gas tube 200. As in the case of the safety cutout operation, breakdown of the gas tube operates the relay E opening its switch 213 and interrupting the starting relay 13 which causes the motor 40 to stop.

In the case of a mechanically jammed rudder, if the gas tube 200 misses operating by a few seconds on the first 180 segment travel of the gyro switch 30, it will operate several seconds sooner on the next 180 segment travel of the switch. This is because the condenser charge is not total, so the charge tends to add up slowly over a series of operations. If the condenser were allowed to charge for about 5 to 8 seconds before each reversal of the relays, the gas tube would break down after a few such intervals, even though the normal operating time is almost twice that value. Below 5' seconds the relays can be reversed indefinitely without breaking down the gas tube. operation in which the relays reverse every second.

Operational summary.-Under this control system, the distance gear is set to operate the distance switch 47 before the torpedo is discharged, and the starting lever switch 10 is closed as the torpedo is expelled. The gyro motor 12 is started and the starting relay 13 is energized if auxiliary starting relay 218 is also energized to close its switch 19. The motor starting switch 27 is closed by its relay winding 25, which also closes a circuit to the relay B of the ACR and SC controls.

After a brief but very high speed impetus of the gyro motor 12, the gyro interrupter switch 16 is opened but the gyro continues operation at high speed which continues throughout the run of the torpedo. If there are no impediments such as sticking of the rudders or relays, the torpedo is now on its way directed on its course by the gyro and controlled as to depth by its depth setting and the depth pendulum unit.

After traveling the predetermined distance, selected to suitably space the torpedo from its sending ship and to place it in the acoustic field of its target, the operation of the distance switch 47 energizes its relay 5t and closes its switch 51 to activate the enabler relay 52 which thereupon connects the hydrophones and their devices and circuits for taking over the control of the horizontal and vertical steering.

When a sufficient acoustical signal is received by the horizontal hydrophones the torpedo is guided toward a target but is maintained at a normal depth of about eighty feet below the surface of the water until it approaches the target. When the angle of approach from the torpedo to the target is about fifteen degrees, the vertical steering relay K4 is released because of the vertical up hydrophone predominance, and the elevator relay 116 is placed in released condition, thereby energizing the up winding and directing the torpedo to a hit.

As the torpedo rises, the depth disarming switch 58 closes and, with the detonator terminals 66 already raised from the safety bar 67, completes an energizing circuit to the fixed block 60 and inertia switch 651, which are joined upon impact with the target to close a circuit from the battery 14 and to the detonator and an explosive charge in the firing head.

In addition to the distance switch which provides that the torpedo is well out of the range of its submarine before becoming acoustically enabled, and the depth disarming switch which disarms the torpedo while it is runing at depths less than 60 feet, there is an inherent This gives a large safety factor for normal I c anges ,characteristic of the acoustic ,system, -including the 8 decibel loss in the up hydrophone channel, which preyehts the torpedo from responding to an acoustic signal arriving from depths less than the set depth of 80 feet. .The anticircular run (ACR) and safety cutout (SC) system stops the torpedo if it turns more than 90 in either direction after firing and before operation of the dis- ,tance switch. This protection extends also to electrical and mechanical failures, so that a jammed rudder, a

, gyro failure or a circuit failure will open the motor control circuit and stop the propulsion motor, thus allowing the torpedo, which has a negative buoyancy of about 250 pounds, to sink harmlessly.

The safety cutout is a protection against the distance switch being closed at the time the torpedo is fired due to the accidental setting of the distance gear at zero, or ,for any other reason, and functions so that the auxiliary starting relay will be operated to stop the motor.

In the event that the torpedo does not hit the target upon any attempt, a lockout arrangement overcomes its tendency to run out of the elfective acoustic target field and to return to its gyro course and control. The gyro lockout control is operated when the relay K4 is released for a period greater than is normal in depth homing. The gas tube 136 is then fired, and the DG relay is energized and closes a circuit through the K2 relay of the gyro bucking differential control. When these connections are made the horizontal bridge circuits of the electronic steering channel device 154 are placed in steady balance through the network in the GBD circuit, and only a small horizontal differential acoustic input, of the order of one-half decibel, is then required to effect steering. The circuit then becomes responsive to the self noise of the torpedo which has enough unbalance to cause a bias to one side or the other. This causes the torpedo to circle until it is attracted by a sound field stronger than its own which causes it to again follow and rise to the attack.

If the distance switch contact switch 51 is closed at the time of firing the torpedo, the ACR-SC relay A will be energized which will start the charging of the condenser 201 of the gas tube 200 through the low resistance 211. The gas tube will be fired in approximately one tenth of a second and the relay B will be operated. This opens the switch 213 of the relay E and the auxiliary starting relay 218 is energized, open ng the motor circuit and removing power from the exploder circuit.

If the distance switch is not closed at the time of firing the torpedo, the relay A will not operate. As soon as the motor start switch 27 is closed by its relay, the relay B will be energized which opens the circuit for the low resistance 211. This effectively removes the safety cutout feature so that the closure of the distance switch 51 at any later time will not disable the torpedo.

While this electrical acoustic torpedo control system has been described in some detail, it should be regarded as an illustration or example and not as a restriction or limitation of the invention, as many changes may be made in the construction, combination, arrangement and connection of the parts without departing from the spirit and scope of the invention.

We claim:

1. In an electrical acoustic submarine torpedo, an elevator rudder and up and down coil means for operating it in opposite directions, an elevator relay for controlling the coil means, a depth pendulum switch unit for energizing or releasing the elevator relay, acoustic means including up and down hydrophones and a relay actuated thereby, a sound loss means in circuit with the up hydrophone so that the sound input to the upper hydrophone must exceed the sound input to the lower hydrophone by the amount of this loss in order for the sound to be equal within the acoustic means, the hydro phone relay having a switch in a circuit including the .peudulumswitch, and a n enabler relay having a switch in a circuit with the hydrophone relay actuated switch to continue the operationof the pendulum unit switch and to hold the torpedo at normal running depth .until it is close to an acoustic target.

2. In an electrical acoustic submarine torpedo, a steering rudder and starboard and port electrical coil means for steering, a steering rudder relay having a switch for energizing one coil means or the other, an elevator rudder and up and down electrical coil means for operating it, an elevator relay having a switch for energizing one of the elevator coil means or the other, gyro controlled switch means for energizing the rudder relay to keep the torpedo upon a predetermined course, a depth pendulum unit including a switch in circuit with the elevator relay for controlling the depth of the torpedo, accoustic means comprising port and starboard and up and down hydrophones, the port and starboard hydrophones having a relay operated by differential horizontal channel sound signals and a switch controlled thereby, the up and down hydrophones having a relay operated by differential vertical channel sound signals, an enabler relay and means for energizing it when the torpedo has traveled a pre determined distance, the up and down relay having a switch in circuit with the depth pendulum unit, and switch means actuated by the enabler relay including a connection with the up and down relay switch for maintaining a circuit through the pendulum unit when the enabler relay is energized, and another connection through the switch of the up and down relay to the rudder relay, and a switch operated by the enabler relay having a connection to the gyro controlled switch means which is opened when the enabler relay is energized to place the steering and elevating rudders under acoustic control through their respective relays.

In an electrical acoustic submarine torpedo, electrical propulsion means, a distance switch actuated by said means, a rudder and electro-responsive means for operating it, gyro means to guide the torpedo by said electroresponsive means, a depth rudder and electro-responsive means for the depth rudder, acoustic means comprising port and starboard hydrophones having a relay operated by differential horizontal sound signals and up and down hydrophones having a relay operated by differential vertical sound signals, a switch operated by the horizontal hydrophone relay, a switch operated by the vertical hydrophone relay, an enabler switch having relay switch means controlled by the distance switch to connect the switches of the horizontal and vertical relays in circuits including the rudder electro-responsive means and the depth rudder electro-responsive means, the enabler switch having means for disconnecting the gyro means for guiding the torpedo when the enabler switch is operated; and a detonating circuit comprising an inertia switch closed upon impact, a depth disarming switch having pressure means open to the outside of the torpedo for opening it at a predetermined depth; and sound loss means in circuit with the up hydrophone which tends to maintain the torpedo at a predetermined depth until it nears a target, and the sound loss being overcome when near the target to direct the torpedo angularly upward to hit the target.

4. In an electrical acoustic submarine torpedo, a detonating circuit including an inertia switch closed upon impact and a depth disarming switch having pressure means open to the outside of the torpedo for opening the switch at a depth below the normal ship striking depth, a horizontal steering rudder and gyro controlled means for operating the rudder to keep the torpedo upon a predetermined course, an elevator rudder and pendulum controlled means for maintaining the torpedo normally at a predetermined depth, acoustic means including port and starboard hydrophones and electro-responsive means operated by differential horizontal sound signals, and up and down hydrophones having electro-responsive means operated by differential vertical sound signals, switch means having electric relays for operating them to disconnect the gyro controlled means for steering and to substitute the horizontal accoustic means for steering and to supplement the pendulum controlled means with the vertical acoustic means for maintaining the torpedo at a predetermined depth, the differential vertical signals received by the up and down hydrophones causing the torpedo to rise when nearing a target, and the depth disarming switch being closed when the torpedo rises so that the detonating circuit is closed by the inertia switch when a target is engaged.

5. In an electrical acoustic submarine torpedo, a horizontal steering rudder and gyro means for controlling the rudder, an elevator rudder and a depth pendulum unit having fluid pressure depth means and relay means adapted to control the elevator rudder, horizontal acoustic hydrophones and vertical acoustic hydrophones at the front of the torpedo, means including a distance switch to maintain the gyro means in steering control, means including an enabler relay for connecting the horizontal and vertical hydrophones to assume control of the steering and elevator rudders over the gyro means and the pendulum unit, sound loss means in connection with the up hydrophone causing it to turn the torpedo in a sharply upward path when it closely approaches a target, and an exploder circuit including a depth disarming switch and an inertia switch closed respectively upon reaching a predetermined depth and upon impact with a target.

6. In an electrical acoustic submarine torpedo, a horizontal steering rudder and gyro means for controlling the rudder, an elevator rudder and a depth pendulum unit having fluid pressure depth means and relay means adapted to control the elevator rudder, horizontal acoustic hydrophones and vertical acoustic hydrophones at the front of the torpedo, means including a distance switch to maintain the gyro means in steering control, means including an enabler relay for connecting the horizontal and vertical hydrophones to assume control of the steering and elevator rudders over the gyro means and the pendulum unit, sound loss means in connection with the up hydrophone causing it to turn the torpedo in a sharply upward path when it closely approaches a target, the hydrophones being disposed forwardly to receive acoustic signals from the front and having little response to acoustic signals from the rear of the torpedo, the torpedo having a sutficient unbalanced self-noise to affect the port and starboard hydrophones when it is acoustically enabled to actuate the steering rudder for turning the torpedo in a circular path to again receive signals from an acoustic source at the front of the torpedo.

7. In an electrical acoustic submarine torpedo, a horizontal steering rudder and gyro means for controlling the rudder, an elevator rudder and a depth pendulum unit having fluid pressure depth means an relay means adapted to control the elevator rudder, horizontal acoustic hydrophones and vertical acoustic hydrophones at the front of the torpedo, means including a distance switch to maintain the gyro means in steering control, means including an enabler relay for connecting the horizontal and vertical hydrophones to assume control of the steering and elevator rudders over the gyro means and the pendulum unit, sound loss means in connection with the up hydrophone causing it to turn the torpedo in a sharply upward path when it closely approaches a target, means to cause the torpedo to circle and resume its preset running depth when an acoustic target is overshot without a hit, the gyro means being operative to assume steering control of the torpedo upon a set course in the absence of an acoustic signal after an overshot, and the hydrophones being operative to assume steering and depth control of the torpedo if a suflicient acoustic signal is received after an overshot from an external source.

8. In an electrical acoustic submarine torpedo, a rudder and gyro switch means for actuating the rudder for steermg upon a predetermined course, acoustic means including port and starboard hydrophones and a relay switch actuated by sound signal differentials between the hydrophones, a propulsion motor and a propeller shaft operated thereby, a distance switch operating device in connection with the propeller shaft, a distance relay switch operated by the device, an enabler relay switch in connection with the distance relay switch and the hydrophone relay switch to substitute sound signal actuation for the gyro switch means in actuating the rudder when the distance switch operating device is operated a predetermined amount by the propeller shaft, a motor start switch for closing a circuit to the propulsion motor, a switch in the motor circuit and a relay for opening it, a circuit for the relay, and electronic timing means including a switch in the circuit for the relay operative to open the circuit before the torpedo can turn 9. In an electrical submarine torpedo, a propulsion motor and an operaitng circuit therefor, a rudder and two electrical devices for turning it oppositely for steering, means for alternately operating the devices in guiding the torpedo upon a predetermined course, the torpedo having an effective turning radius which requires a known time for a predetermined circular course, and anti-circular run means actuated by one of said electrical devices when it is continuously operated for a predetermined time and operative to open the motor circuit.

10. In an electrical submarine torpedo, a propulsion motor and an operaitng circuit therefor, a rudder and two electrical devices for turning it oppositely for steering, means for alternately operating the devices in guiding the torpedo upon a predetermined course, the torpedo having an effective turning radius which requires a known time for a predetermined circular course, and anti-circular run means, comprising an electronic tube and a condenser in circuit for firing the tube, means in connection with each electrical device for partially charging the condenser when the devices are operated and discharging the condenser when they are alternately operated, the tube being fired by the condenser when one of said devices is continuously operated for a predetermined period of time, and electroresponsive means operated by the tube when it is fired to open the motor circuit and stop the motor.

11. In an electrical submarine torpedo, a propulsion motor having a main switch circuit and an operating circuit therefor, a distance switch normally closed after the torpedo has been driven a predetermined distance by the motor, an electronic tube having a relay switch operated thereby and connected in the motor operating circuit, a condenser for charging the tube to operate the relay, a relay switch in a circuit depending upon closure of the distance switch, and operative to close a circuit to charge the condenser, and a safety-cutout relay switch in a oircuit closed by the main switch and having a back contact which closes a circuit for the relay switch operated by the electronic tube, the-firing of the tube by the condenser operating the relay switch to open the motor operating circuit and preventing closure of the main motor switch circuit if the distance switch is prematurely closed.

12. In an electric submarine torpedo, a propulsion motor having a main switch circuit and an operating relay circuit therefor, a distance switch normally closed after the torpedo has been driven a predetermined distance by the motor, and a safety cut-out for preventing the motor from running if the distance switch is prematurely closed comprising an electronic tube with a condenser for firing it and a relay switch in the operating relay circuit to open the main motor circuit, a pair of relays one having a circuit depending upon the closure of the distance switch and effective to close a circuit to the condenser, and the other closed with the main motor circuit and having two switches normally closed one to close a circuit through the condenser when the other of the pair of relays is first energized and the other switch to connect the electronic relay switch winding in an operating circuit, the electronic relay switch being in the circuit with the motor operating 17' relay to prevent the motor from, starting when the distance switch is open.

13.. In an electric submarine torpedo, a propulsion motor having a main operating circuit and a relay operating circuit therefor, a rudder and two electrical devices for turning the rudder oppositely for steering, a distance switch normally closed after the torpedo has been driven a predetermined distance by the motor, means for operating the devices alternately in guiding the torpedo upon a predetermined course, anti-circular run means comprising an electronic tube and a condenser in circuit for firing the tubes, a relay operated by the tube when it is fired having a switch controlled thereby in the motor relay operating circuit, the tube being fired by the condenser when one device is continuously operated to produce a circular run of the torpedo, and safety cut-out means comprising a relay having a winding in a circuit depending upon the closing of the distance switch, and the relay switch operative to close a circuit to the condenser and to energize the tube relay to open the motor relay operating circuit, and another relay having its winding in a circuit closed with the main motor circuit, and a switch to open a connection through the other cut-out relay switch preventing the closing of a circuit to the condenser when the distance switchis not prematurely closed.

14. In an electric submarine torpedo, a propulsion motor having a main operatingcircuit and a controlling circuit therefor, a rudder and two electrical devices for turning the rudder oppositely for steering, means for operating the devices alternately in guiding the torpedo upon a predetermined course, and a combined anti-circular run and safety cut-out device comprising electronic tube means having a firing condenser and a relayenergized when the tube is fired, relay switch means to close a circuit to the condenser when either electrical device is energized and to discharge the condenser when the devices are energized alternately, the tube being fired when only one device is energized to produce a predetermined circular run, the tube relay having a switch opened when the tube is fired and in the controlling circuitto stop the motor, and a pair of relay switches one having an operating circuit dependent upon the continued operation of the motor after starting and operative .toclose its switch in a circuit to charge the condenser and the other having a winding connected in a circuit from the main operating circuit and having switches normally closed toconnectthe first of the pair of relay switches through its switch to the condenser and the other switch to connect the tube relay winding in its energizing circuit from the tube, this'tube relay having a holding contact and a switch for connecting its Winding through the switch rather than through the said other switch of the-second of the pair of relays.

15. In an electrical acoustic submarine torpedo, a rudderand electrical means to oppositely actuate it for steering, gyro means for maintaining the'torpedo-upon a predetermined course comprising a gyro repeater relay switch operated "by the gyro means, and a rudder relay controlled by the repeater relay switch; horizontal hydrophones and electronic means for receiving acoustic signals, including a horizontal-bridge circuit device and a steering control switch-relay operated thereby; a distance switch operated by thetorpedo after moving a predetermined distance, an enablerrela-y-having its winding in circuit with the distance switch anditsswitch connected with a switch of the steering control switch relay and in ,Circuit with the rudder-relayfor energizing it; and gyro bucking differential 'circuit means comprising a potentiometer ;in circuit with the "repeater relay switch having terminal points connected to the horizontal bridge circuit device to operate in step with the gyro means and to unbalance the bridge circuit alternately in opposite directions for steering when the sound differential has sufficient acoustic input to operate the steering control relay.

16. In an electrical acoustic submarine torpedo, a rudder and electrical means to actuate it oppositely for steer- 18 ing, gyro. means for controlling the electrical means to maintain the torpedo upon a predetermined course, horizontal hydrophones activated by acoustic signals havingv electronic means for differentiating the signals and in cluding a steering relay, vertical hydrophones activated by acoustic signals having electronic means for differentiating the signals and including a vertical steering relay, a vertical elevator rudder and means for operating it including a circuit having therein a switch operated by the vertical steering relay, a gyro bucking difierential circuit connected to the electrical means for actuating the steering rudder as controlled by the gyro means and including a circuit having a switch therein operated by the steering relay and unbalancing connections to the electronic means for the horizontal hydrophones to control the steering relay according to the acoustic signals received, a distance switch operated when the torpedo has traveled a predetermined distance, an enabler relay switch actuated by the distance switch and having switches for completing circuits through the horizontal steering relay switch and the vertical elevator relay switch, and lock out means in connection with the vertical elevator switch including a timing tube and a circuit controlled thereby including a relay switch in the gyro differential circuit to disconnect the differential circuit from its unbalancing connections and to place the electronic means for the horizontal hydrophones in substantially steady balance so that only a small horizontal difterentialinput is necessary to effect steering thereby.

17. In an electrical acoustic submarine torpedo, port and starboard hydrophones, relay means operated thereby, rudder actuating means controlled by said relay means, gyro means for alternately operating the rudder actuating means to maintain the torpedo upon a predetermined course, enabling means for connectingthe relay means operated by the hydrophones to take over the rudder actuating means from the gyro means when the torpedo has traveled .a predetermined distance, gyro bucking difierential means tending to unbalance the port and starboard hydrophones in step with the gyro means when the hydrophones take over the operation of the rudder actuatingmeansdue to diiierential acoustic signals of predetermined intensity, and lock-out means to nullify the unbalancing action of the bucking differential means and toeffect the operation of the hydrophone relaymeans by a differential signal of less than said predetermined intensity.

18. In an electrical acoustic submarine torpedo, a steering rudder and relay means for controlling it, gyro means for alternately. actuating and releasing the relay means for maintaining the torpedo upon a predetermined course, port and starboard hydrophones activated by a differential sound signal and relay means operated thereby, a distance switch operated when the torpedo has traveled a predetermined distance, an enabling switch relay activated :by the distance switch to substitute the hydrophone relay for the gyro means of steering control, a gyro bucking differential circuit for receiving opposite impulses from the gyro means and impartingunbalancingpulses to thehydrophones which requires a high acoustic difierential input between the hydrophones to operate the 'hydrophone relay, the torpedo having a self-noise which must be exceeded by the differential acoustic input order to activate the hydrophone relay to take overacou stic control of the rudder relay means, a vertical elevator rudder and relay means including an'operating circuit for operating the elevator rudder,-up .and down'hydrophones and a relay operated by a-ditferential sound input between them, this last relay having a switch in the vertical elevator circuit, and a lock-out circuit closed by the release of the switch of the vertical elevator relay and operative to close a timed circuit to the gyro bucking differential circuit operative to nullify the unbalanced pulses and to place the hydrophones in close balance so that a small horizontal diflerential sound input is re- '19 quired to effect the operation of the steering hydrophone relay, the steering hydrophones being then sensitive to the self noise of the torpedo to cause steering response to one side or the other until attracted by a stronger sound field.

19. In an electrical acoustic submarine torpedo, a propeller motor and circuit means therefor, a rudder and relay means for operating it oppositely for steering, gyro means for actuating the relay means to maintain the torpedo upon a predetermined course, horizontal hydrophones for steering and vertical hydrophones for elevational guidance, distance switch and enabler relay means for connecting the hydrophones to substitute them for the gyro means for steering, gyro bucking differential means for unbalancing the horizontal hydrophones in step with the gyro means, lock-out circuit means actuated by the vertical hydrophones for nullifying the unbalancing of the gyro bucking differential means making the horizontal hydrophones more sensitive to differential sound signals, timing means depending for operation upon the actuation of the enabler relay for preventing a predetermined circular run of the torpedo, and safety cut-out means for opening the circuit means of the propeller motor if the distance switch is closed when the torpedo is launched.

a 20. In an electrical acoustic submarine torpedo, a rudder and relay means for operating it oppositely for steering, gyro means for actuating the relay means to maintain the torpedo upon a predetermined course, horizontal hydrophones for steering and vertical hydrophones for elevational guidance, distance switch and enabler relay means to connect the hydrophones to substitute them for the gyro means for steering, gyro bucking differential means for unbalancing the horizontal hydrophones in step with the gyro means to require a higher acoustic input before the horizontal hydrophones take over the steering, lock-out circuit means comprising an auxiliary gate relay actuated by the vertical hydrophones when a source of acoustic energy of more than predetermined magnitude is above the torpedo, an electronic timing tube and a firing condenser in circuit therewith, the auxiliary gate relay having a switch operated thereby connected with the tube and condenser and operative when actuated by the vertical hydrophones relay to charge the condenser, said tube becoming conductive after said condenser has been charged to a predetermined magnitude, a delayed gate relay activated by the timing tube when it becomes conductive, and a switch operated by the delayed gate relay in a control circuit with the gyro bucking differential means to nullify the unbalancing thereof and thereby to make the horizontal hydrophones more sensitive to differential sound signals for steering.

21. In an electrical acoustic submarine torpedo, port and starboard hydrophones, relay means operated thereby, rudder actuating means controlled by said relay means, gyro means for alternately operating the rudder actuating means to maintain the torpedo upon a predetermined course, enabling means for connecting the relay means operated by the hydrophones to take over the rudder actuating means from the gyro means when the torpedo has traveled a predetermined distance, gyro bucking differential means tending to unbalance the port and starboard hydrophones in step with the gyro means to require a higher acoustic input when the hydrophones take over the operation of the rudder actuating means, an up and down elevator rudder for controlling the depth of the torpedo, up and down hydrophonesalso connected for operation of the rudder, sound loss means in connec- 20 tion with the up hydrophone requiring the torpedo to be relatively close to a sound source before the torpedo is turned upwardly from a predetermined running depth, depth unit means for turning the torpedo downwardly after it has'over-shot an acoustic target without making a strike, and a lock-out circuit activated by the sound differential in the up and down hydrophones to nullify the unbalance of the horizontal hydrophones so that a differential sound input of lower intensity is required to effect the operation of the steering hydrophone relay, and the steering horizontal hydrophones being then sensitive to an unbalance of the self-noise of the torpedo to turn the torpedo into the gyro course and to return it to an attack if it is again attracted by a stronger acoustic signal.

22. In an electrical acoustic submarine torpedo, steering means for guiding the torpedo in the horizontal plane, electrical actuating means for said steering means, gyroscopic means for controlling said actuating means to steer said torpedo on a preselected course, acoustic means for controlling said actuating means to steer said torpedo toward a source of acoustic energy, enabling means for permitting said acoustic means to override said gyroscopic means and control said electrical actuating means after said torpedo has traveled more than a predetermined distance if the torpedo is within the sound field of said source and if said sound field is above a predetermined minimum value, and means for disconnecting said gyroscopic means from said electrical actuating means after the sound source has been detected for more than a predetermined period of time.

23. In an electrical submarine torpedo, depth steering means for steering said torpedo in the vertical plane, electrical actuating means for said depth steering means, depth control means for controlling the electrical actuating means to cause said torpedo to operate at a predetermined depth, acoustic means for controlling said electrical actuating means to steer the torpedo toward a source of acoustic energy, and enabling means for permitting said acoustic meansto override said depth control means to steer said torpedo toward said source after the torpedo has traveled more than a predetermined distance and if the sound field of said source is above a predetermined minimum value, said depth control means adapted to control said electrical actuating means and return said torpedo to said predetermined depth in the event that said source of acoustic energy is lost after having been detected.

24. In an electrical submarine torpedo, a rudder, gyro scopic means for operating the rudder to keep the torpedo substantially upon a preselected course, a propulsion motor having motor control means, and means for causing said motor control means to stop said propulsion motor when said rudder is maintained in a position to cause the torpedo to turn in a given direction for more than a predetermined period of time.

References Cited in the file of this patent UNITED STATES PATENTS 478,813 Paine July 12, 1892 1,121,563 Leon Dec. 15, 1914 1,598,107 Trenor Aug. 31, 1926 1,855,422 Roussey Apr. 26, 1932 2,382,058 Hull Aug. 14, 1945 2,419,164 Putman et a1 Apr. 15, 1947 2,537,929 Daly et al. Jan. 9, 1951 2,538,156 Keto Jan. 16, 1951 2,572,116 Daly'. Oct. 23, 1951 

